Fiber optic systems are now in common use for transmitting optical communication signals (i.e., optical signals modulated to encode desired information). Optical communication signals are transmitted across a network using optical fibers that support substantial transmission capacity with compact fiber bundles. Given the ever-increasing demands for improved signal quality and bandwidth, it is anticipated that the use of fiber optic communications will continue to increase for years to come.
In addition to bandwidth density advantages, a further reason why fiber optic networks have attracted attention in recent years relates to potential switching advantages. Conventional electronic switching components create bottlenecks in network communication, particularly when switching high bandwidth signals. Because the communication signals in fiber optic networks are optical rather than electrical in nature, bottlenecks caused by conventional electronic switching components potentially may be eliminated. A variety of optical switching technologies are reputed to be under development, including MEMS micromirror array switches and ‘bubble’ or ‘droplet’ switches utilizing inkjet dispensing technology. Questions remain, however, about fabrication difficulties and/or robustness of these devices, and commercial embodiments of these technologies have yet become widely available. There remains a commercial need for robust optical switching devices that may be readily manufactured.
There also exist needs for active optical devices in other fields not necessarily directed to optical switching. For example, in research environments it is often desirable to provide electromagnetic radiation to a test sample, then vary a characteristic of that radiation (such as, for example, intensity or spectrum), and finally detect or measure some interaction with the sample as a function of the supplied radiation. Collimated, polarized, monochromatic, and/or laser light is often desirable in such environments. Conventional methods of varying radiation characteristics from a fixed source include placement of filter elements between the source and a sample. To facilitate rapid changing of elements, filter “wheels” having multiple elements may be provided in the path of the incident beam. However, such methods involving discrete filter elements are digital in nature, thus limiting their ability to vary filtering utility in very small increments. As a result, there exists a need for dynamic optical devices that may be continuously varied.
The present invention provides, inter alia, novel devices and methods that can be used for switching communication signals in fiber optic networks, for dynamic optical devices, and for other applications that require manipulation of light waves.